RME VHF-152A converter

The RME (Radio Manufacturing Engineers) VHF-152A is a converter for the 10, 6, and 2 meter ham bands. Vintage 1947. As shown in this picture from a 1948 RME ad, it matches the height and cosmetics of the RME-45B receiver but was used with a variety of other receivers as well.See also the matching RME DB-22A preselector and the HF-10-20 converter.

The converter uses a 6AK5 as RF amplifier and a 6J6 as oscillator/ mixer. Power is supplied via a 5Y3 with a VR-150 voltage regulator tube for stability. Output is 7 MHz.

The VHF-152A converter provides double conversion, with the companion receiver set at 7 MHz as a fixed IF. Like its HF-10-20 brother, this converter is also an excellent accessory for a fixed-frequency receiver that can be fixed at 7 MHz. (For an example, see the Navy FRR-26 receiver.

RepairsAfter a thorough cleaning, application of deoxit on the controls and sockets, and the usual safety checks and slow power-up, I found this device was in good working order. No repairs were needed. This was the same experience I had with the HF-10-20. A thorough cleaning and alignment was all that was needed.

The RME manual, schematic and alignment instructions can be downloaded from BAMA as well as from Nostalgiaair. It is listed in Rider volume 17, RME pages 1-10 and in Sams Photofacts 51, set 18.

AlignmentI found the alignment on this unit to be off considerably. It took some effort to get the oscillator to track at reasonable accuracy. Of the bands covered by the VHF-152A, my primary interest is 6 meters. After adjusting the oscillator, mixer and RF with a signal generator and frequency counter, I followed a bit of advice in the manual. That was to tweak the 6 meter RF adjustment with the intended antenna attached. This made a considerable improvement in sensitivity.

PerformanceThe companion receiver I am currently using with the converter is a Lafayette HA-800B, a vintage ham-bands-only solid-state receiver. The Lafayette actually covers the 6 meter band but performance is relatively poor. The 6 meter performance of the VHF-152 in combination with the Lafayette is decent given the age the VHF-152. The Lafayette, with its full width coverage of the 40 meter band, allows a bit of bandspread at the 7 MHz conversion point, great for fine tuning the RME. However, for weak signal reception, when compared with my Gonset Communicator III, the Communicator was clearly better.